Classification Of Metamorphic
rocks have been variously classified on the basis of texture and structure,
degree of metamorphism, mineralogical composition and mode of origin etc.
Ø A very
general two-fold classification based on the presence or absence of layered
FOLIATION as defined above is as follows:
metamorphic rocks showing development of conspicuous parallelism in their
mineralogical and structural constitution falling under the general term
foliation are grouped together as foliated rocks.
parallelism indicating features include slaty cleavage, schistosity and
Typical rocks included in this group are slates,
phyllites, schists and gneisses of great variety.
Included in this group are all those metamorphic rocks characterised with total
or nearly total absence of foliation or parallelism of mineralogicaJ
Ø Typical examples of non-foliated rocks are
quartzites, hornfels, marbles, amphibolites and soapstone etc.